Senator Elizabeth Warren [D, Mass] asked for more research into medical marijuana and painkiller addiction in a letter to the CDC director, Thomas Friedan.

“Opioid abuse is a national concern and warrants swift and immediate action,” Warren wrote.

Her request comes as politicians, including the presidential nominees, search for the best response to the opioid epidemic.

The use of prescription opioids doubled between 2000 and 2014, according to the CDC. And Massachusetts experienced its highest number of unintentional opioid overdose deaths in 2014, with nearly 1,100 people succumbing to overdose deaths.

Warren applauded the CDC’s actions so far to curb the epidemic but called on the agency to look at whether medical marijuana could be an alternative painkiller.

She also urged the agency to quickly finalize its guidelines for prescribing opioids for chronic pain and called for increased collaboration between the CDC and other federal health agencies to determine the long-term effects of opioid use in children and the increased use of the powerful synthetic opioid fentanyl.

Nestled in with these recommendations is a call to consider the role of marijuana legalization in the crisis. Specifically, Warren requested the agency to provide more information on “the use, uptake and effectiveness of medical marijuana as an alternative to opioids for pain treatment in states where it is legal”.

The idea: Medical marijuana is an effective painkiller, so it can substitute some opioid painkillers that have led to the current abuse and overdose epidemic. And since marijuana doesn’t cause deadly overdoses and is less addictive than opioids, replacing some use of opioids with pot could prevent some overdose deaths.

The best review of the research to date on medical marijuana, published in the Journal of the American Medical Association, looked at 79 studies that tested cannabis’s medicinal effectiveness among nearly 6,500 patients.

And marijuana was linked to short-term adverse effects such as dizziness, dry mouth, nausea, fatigue, drowsiness, and confusion.

So the evidence suggests marijuana is good for treating chronic pain without any huge side effects.

A working paper from David Powell and Rosalie Pacula of the RAND Corporation and Mireille Jacobson of the University of California Irvine concluded, “Our findings suggest that providing broader access to medical marijuana may have the potential benefit of reducing abuse of highly addictive painkillers.”

The researchers looked at both treatment admissions for opioid pain reliever misuse and state-level opioid overdose deaths. They found relative decreases in misuse and deaths in states with medical marijuana dispensaries, but they didn’t find decreases in states that allow medical marijuana without dispensaries. So the big factor in reducing misuse and deaths seemed to be not just medical marijuana legalization but also access to medicinal pot through dispensaries.

The study also found that legal opioid painkiller distribution didn’t seem to decline in states with pot dispensaries, which, according to researchers, suggests people are replacingillegally obtained opioids with pot. But the overall result is still less misuse and fewer deaths.

Pacula and Jacobson’s research isn’t the first to produce these kinds of results. Another study, published in JAMA, found medical marijuana laws reduce opioid overdose deaths, although it was less rigorous than Pacula and Jacobson’s analysis.

So it’s nice to see Sen. Warren on board with cannabis and hundreds of people in Massachusetts who are addicted to opioids now being treated with medical marijuana..